Device for measuring package size

Abstract

A package measurement apparatus comprising three measurement devices, one for each dimension. Each measurement device comprises a plurality of signal receptor modules. Each module comprises a row of signal receptor, and a signal energy source. In a first calibration step, the outputs of each receptor are standardized to reference maximums and minimums. In a second calibration step, calibration sets of receptor outputs are created and recorded. During measurement, a measurement set of receptor outputs is obtained and matched with a calibration set of receptor outputs to determine the dimension of an object.

1. An apparatus for measuring at least one dimension of a package, the device comprising:
 a dimension measuring device extending along a measurement axis and being sized and shaped to receive a package at a measurement position, and a central processor configured to communicate with said dimension measuring device, receive dimension information, and determine said dimension; 
 the dimension measuring device comprising a plurality of receptor modules detachably connectable to one another; 
 each receptor module including a plurality of signal receptors spaced along said measurement axis; 
 the receptor modules being connected in series, with each receptor module being configured such that all of said plurality of receptor modules are in communication with said central processor to facilitate receipt by the central processor of dimension information; 
 each receptor module including its own local controller associated with the plurality of signal receptors, the local controller containing calibration information for the plurality of signal receptors. 
 
     
     
       2. The apparatus as claimed in  claim 1 , wherein each receptor module is configured to be capable of communicating with said central processor through one or more other receptor modules. 
     
     
       3. The apparatus as claimed in  claim 2 , wherein each receptor module is configured to permit communication between at least one other receptor module and the central processor. 
     
     
       4. The apparatus as claimed in  claim 1 , wherein the local controller is configured to receive raw dimension information from said plurality of signal receptors, apply said calibration information to said raw dimension information to produce adjusted dimension information, and transmit said adjusted information to said central processor. 
     
     
       5. The apparatus as claimed in  claim 1 , wherein the calibration information comprises a mapping function mapping the maximum response of each of said plurality of signal receptors to a predetermined reference maximum and mapping the minimum response of each of said plurality of receptors to a predetermined reference minimum. 
     
     
       6. The apparatus as claimed in  claim 5 , wherein the reference maximum and reference minimum are constant between receptor modules. 
     
     
       7. The apparatus as claimed in  claim 6 , wherein the local controller is configured to receive raw dimension information from said plurality of signal receptors, apply said calibration information to said raw dimension information to produce adjusted dimension information, and transmit said adjusted dimension information to said central processor. 
     
     
       8. The apparatus as claimed in  claim 1 , wherein each receptor module is configured such that the space between adjacent receptors on each receptor module is constant. 
     
     
       9. The apparatus as claimed in  claim 1  or  claim 8 , wherein each receptor module is configured such that the space between adjacent signal receptors on the dimension measuring device is constant. 
     
     
       10. The apparatus as claimed in  claim 1 , wherein the local controller is configured to receive calibration data prior to the receptor module being connected to the dimension measuring device, store said calibration data, and apply said calibration data to the measurement of packages using the dimension measuring device. 
     
     
       11. The apparatus as claimed in  claim 1 , wherein each receptor module further comprises a signal source. 
     
     
       12. The apparatus as claimed in  claim 11 , wherein said signal source comprises a uniform signal source. 
     
     
       13. The apparatus as claimed in  claim 12 , wherein said uniform signal source comprises a plurality of signal points positioned in close proximity to one another to produce a substantially uniform signal over the length of the receptor module. 
     
     
       14. A method of calibrating a plurality of signal receptors, the method comprising the steps of:
 for each receptor, 
 (a) exposing the receptor to a maximum signal; 
 (b) measuring the receptor's output from said maximum signal; 
 (c) exposing the receptor to a minimum signal; 
 (d) measuring the receptor's output from the minimum signal; 
 (e) determining a mapping function that maps the output from the maximum signal to a predetermined reference maximum and maps the output from the minimum signal to a predetermined reference minimum; 
 (f) storing the mapping function for use in multiple measurements. 
 
     
     
       15. A method as claimed in  claim 14 , wherein the storing step comprises storing said mapping function in a local controller associated with the receptor module. 
     
     
       16. A method as claimed in  claim 14 , wherein the storing step comprises storing the mapping function in a central processor of a dimension measuring apparatus. 
     
     
       17. A receptor module, comprising:
 a plurality of signal receptors positioned generally in a row, and a substrate carrying said plurality; 
 detachable connection means for connecting said receptor module to other receptor modules in series to form a dimension measuring device with signal receptors positioned along a measurement axis; 
 the receptor module further comprising its own local controller, associated with said plurality of receptors, the local controller being configured to store calibration information for said plurality of signal receptors prior to use. 
 
     
     
       18. A receptor module as claimed in  claim 17 , wherein the receptor module is configured to communicate, through at least one other receptor module, with a central processor. 
     
     
       19. A receptor module as claimed in  claim 17 , wherein the receptor module is configured to permit at least one other receptor module to communicate with a central processor through said receptor module. 
     
     
       20. A receptor module as claimed in  claim 17 , wherein the space between adjacent signal receptors is constant. 
     
     
       21. A receptor module as claimed in  claim 20 , wherein the signal receptors are positioned such that when the receptor module is connected in series with other receptor modules to form a dimension measuring device, the space between adjacent signal receptors of the dimension measuring device is constant. 
     
     
       22. A receptor module as claimed in  claim 17  wherein said module is configured to be calibrated prior to use and to replace other receptor modules within a dimension measuring device without repeating said calibration prior to use. 
     
     
       23. A method of determining the size of a dimension of an object, the method comprising the steps of:
 placing the object at a measurement location associated with a dimension measuring device comprising a line of signal receptors; 
 actuating a signal source; 
 obtaining a measurement set of receptor outputs; 
 accessing stored calibration sets of receptor outputs, wherein each calibration set of receptor outputs is associated with a particular dimension size; 
 selecting a calibration set of receptor outputs that is closest to the measurement set of receptor outputs; 
 using the particular dimension size associated with said closest calibration set of receptor outputs, determining the size of a dimension of an object. 
 
     
     
       24. A method as claimed in claimed in  claim 23 , wherein the accessing step comprises the step of accessing stored calibration sets of receptor outputs obtained according to the following method:
 selecting a group of N adjacent receptors; 
 positioning at least one calibration object at each of a plurality of positions within an effect area of said N adjacent receptors to simulate measured objects having edges at each of said positions; 
 actuating a signal source when a calibration object is placed at each position; 
 reading a calibration set of receptor outputs for each of said positions. 
 
     
     
       25. A method as claimed in  claim 24 , wherein step of selecting a calibration set of receptor outputs that is closest to the measurement set of receptor outputs comprises the steps of (i) for each group of N adjacent receptors, attempting to match the measurement set of receptor responses to a calibration set of receptor responses associated with said group of N adjacent receptors, and (ii) finding said closest calibration set of receptor responses and identifying the group of N adjacent receptors with which the closest calibration set of receptor responses is associated. 
     
     
       26. A method as claimed in  claim 25 , wherein the consecutive groups of N adjacent receptors are non-overlapping. 
     
     
       27. A method as claimed in  claim 25 , wherein the wherein the consecutive groups of N adjacent receptors are overlapping. 
     
     
       28. A method as claimed in  claim 23 , wherein N comprises an integer greater than 1. 
     
     
       29. A method of calibrating a dimension measuring device that comprises a line of signal receptors, the method comprising:
 selecting a group of N adjacent receptors; 
 positioning at least one calibration object at each of a plurality of positions within an effect area of said N adjacent receptors to simulate measured objects having edges at each of said positions; 
 actuating a signal source when a calibration object is placed at each position; 
 reading a calibration set of receptor outputs for each of said positions, wherein at least one output in the calibration set of receptor outputs is higher than a minimum of a corresponding receptor and a lower than a maximum of the corresponding receptor; and 
 storing said calibration sets of outputs for use during object measurement. 
 
     
     
       30. A method as claimed in  claim 29 , wherein N equals 3. 
     
     
       31. A method as claimed in  claim 29 , wherein the storing step comprises the step of storing said storing said calibration sets of outputs in the memory of a central processor. 
     
     
       32. A method as claimed in  claim 29 , wherein the reading step comprises reading a calibration set of receptor outputs wherein the receptor outputs are adjusted to standardize the outputs across all receptors.